Chronic orofacial pain is a common clinical syndrome lacking specific and effective therapeutic agents due to the fact that cellular mechanisms of chronic orofacial pain are poorly understood. Based on data from in vitro biochemical studies and non-orofacial, nerve injury-induced chronic pain models, we hypothesize that trigeminal nerve injury leads to altered expression of the calcium channel alpha-2-delta-1 subunit (Cava2d1) and thrombospondin-4 (TSP4) in trigeminal ganglia and associated brainstem and upper cervical spinal cord that plays a functional role in the development of neuropathic pain by promoting synaptogenesis. In this Competitive Revision, we plan to test if nanoparticle encapsulated antisense oligonucleotides against the Cava2d1 and TSP4 mRNA better efficacy than free antisense oligonucleotides in reversing Cava2d1 and/or TSP induction by injury and blocking orofacial neuropathic pain development, respectively. In addition, we plan to use electrophysiology recording techniques to define if injury-induced expression of these proteins play an important role in altering spinal synaptic transmission. Completion of these studies will allow us to expand the scope of the original proposal and to expand the goals of the original project to accelerate the tempo of scientific research in identifying new targets and pathways for the development of new medications for orofacial pain management. PUBLIC HEALTH RELEVANCE: Chronic orofacial pain derived from nerve injury, or orofacial neuropathic pain, is a common clinical syndrome lacking specific and effective therapeutic agents due to the fact that its cellular mechanisms are poorly understood. Existing data from in vitro biochemical studies and non-orofacial nerve injury pain models support that trigeminal nerve injury may lead to altered expression of the calcium channel alpha-2-delta-1 subunit (Cava2d1) and thrombospondin-4 (TSP4) in trigeminal ganglia and associated brainstem and upper cervical spinal cord that plays a functional role in orofacial pain development through a novel mechanism. In this exploratory proposal, we plan to test if trigeminal nerve injury causes altered expression of the Cava2d1 and TSP4 that contributes to the genesis and/or maintenance of neuropathic pain in an orofacial neuropathic pain model. We proposed to test this hypothesis using biochemical and behavioral pharmacology approaches in the parent proposal. In this revision proposal, we plan to expand the scope of the original proposal to include two new aims. One is to use novel nanotechnology in delivering agents with therapeutic potential to block injury-induced orofacial pain and target gene regulation. Second one is to use electrophysiology recording to see if injury-induced changes cause alterations in synaptic neurotransmission in the spinal cord that leads to orofacial pain. Completion of this study will allow us to expand the scope of the parent proposal and accelerate the tempo of scientific research in this under investigated field and the discovery of new drug targets for chronic pain disorders.